1. Field of the Disclosure
The present disclosure relates to a peak current limiting apparatus, and more particularly to a peak current limiting apparatus capable of limiting a fault current more than a threshold value to thereby protect electric appliances connected to electric power systems.
2. Discussion of the Related Art
An electric power system is generally mounted with a current limiter for limiting a fault current more than a threshold value in order to protect against burning and damage by the fault current caused by accidents such as thunder-stroke, earth fault and short-circuit, and a circuit breaker for detaching itself to prevent the fault current from load.
The current limiter serves to limit a fault current more than a threshold value to reduce mechanical, thermal and electrical stresses caused by electric power appliances such as, for example, bus bars, insulators and circuit breakers to a minimum and to protect the electric appliances against the fault current.
On the other hand, a circuit breaker connected to an electric power system detects an over-current more than a threshold value, breaks the connection with the electric power system in accordance with control of an over-current relay generating a breaking signal and thus prevents the over-current from flowing into the electric power system.
Meanwhile, 3 to 5 periods of the fault current are required in a circuit breaker for breaking an over-current more than a threshold value in response to control of an over-current relay, which is due to the fact that a considerable time is required for the over-current relay to detect a fault current exceeding a threshold value.
As a result, the over-current relay may suffer from a drawback that it cannot detect the fault current if the current limiter is operated earlier than a time when the fault current exceeding the threshold occurs to thereby limit the fault current that exceeds a predetermined level.